The manager of the care home where 17-year old "Ray" spent the first 10 days after seeking help from authorities at Berlin's City Hall described him as a "normal teenager".

Despite claims that he spent the last five years living rough in the forest with his father, before burying him after a fatal fall last month, the boy soon adapted to life in a hostel with other youngsters.

"He had moments where he appeared uneasy but generally he settled in well and appeared comfortable," said Berte Kohn, the manager of the Jugendnotdienst youth shelter, in Berlin's Charlottenburg district.

He was quiet and communicated little with the other teenagers, who come from troubled backgrounds, she said, because they spoke little English and he had only a few words of German.

"But there were no problems with him and he seemed happy to be inside, to sleep in a comfortable bed and take regular showers," she said. "He mixed with the others like a normal teenager but spoke little."

During the 10 days he spent at the centre before being transferred to another residence within the youth care system, he was visited several times by police, psychologists, and linguistic experts.

But police admitted on Tuesday that initial investigations had led nowhere.

"We have tried psychologists – as a means of getting more information from him – but without success," confirmed Klaus Shubert, a Berlin police spokesman.

And despite several visits from so-called linguistic experts police were no closer to establishing his nationality.

"We just don't know if he's British or from elsewhere," said Mr Schubert. "He speaks English but it seems his accent is hard to pin down."

"The important thing is that he seems OK and is in good condition. The rest we will have to wait for. We are making inquiries but it could take some time," he added.

Interpol has so far failed to come up with any information that could lead to the boy being properly identified.

Its National Central Bureau in Wiesbaden is coordinating efforts on the request of the German National Police in a bid to discover his origins.

"The problem is that this is not a typical case of locating missing person," said a source at Interpol Headquarters in Lyon, France. "Instead, we are dealing with a 'found' person who has no information about who he is or where he has been."

Berlin Police said that further progress towards discovering the boy's identity might be made with the discovery of his father's body as his fingerprints could match those on a police database somewhere.

The teenager, who claims he and his father Ryan, took to the woods after his mother, Doreen, died in a car crash five years ago, claimed he buried him in a shallow grave before walking north to Berlin.

Police said they have asked forces in the south of the country as well as across the border in the Czech Republic and Austria to inform them if a corpse turns up.